According to the Universal Writing System Constraint, all writing systems encode language, and thus reflect basic properties of the linguistic system they encode. According to a second universal, the Universal Phonological Principle, the activation of word pronunciations occurs for skilled readers across all writing systems. We review recent research that illustrates the implications of these two universal principles both across and within writing systems. Within the family of alphabetic systems, differences between Korean and English arise in the languages, rather than the orthographies, while the reverse appears to be true for German and English differences. Across writing systems, new Event Related Potentials (ERP) experiments show the robustness of phonology across Chinese and English systems and chart the time course of word reading in Chinese and English for Chinese bilinguals and for English speakers learning Chinese. The ERP results show differences between Chinese and English for both groups and suggest that the time course of word processes and the brain areas identified as sources for the ERP components differ both as a result of writing system and the skill of the reader. We propose the System Accommodation Hypothesis, that reading processes and the neural structures that support them accommodate to specific visual and structural features of a new writing system.